When casting to XML type from other SQL types, an XML value of the nearest xml schema primitive type is created. For example, xs:string for VARCHAR/CLOB and xs:date for DATE.
When casting from XML type to other SQL types, the string value of the XML instance should be compatible with the target data type. For example, xs:date value being cast to SQL DATE type.
Casts to and from XML type are supported for the following data types.
Casting to XML type from large object types (CLOB and BLOB) is subject to a limitation that only values up to 64KB in size can be cast successfully.
When casting from XML type to VARCHAR or CLOB, only the UNICODE character set is supported for the target data type.
When casting to XML type, you can specify the inline length so that the resulting XML data type can be a LOB type or a non-LOB type.